There has been a lot of interest recently in bioaerosols due to bioterrorism events and increased awareness of health related problems due to environmental bioaerosols. This talk will give an overview on characteristics of bioaerosols, bioaerosol sampling, and examples of emerging bioaerosol samplers and analyzers for detecting bioterrorism events. The standard unit currently in use is the Agent-Containing Particles per Liter of Air (ACPLA) and the appropriateness of this unit is very important for detecting a threat. This talk will discuss the alternate measures proposed by others to quantify bioaerosol threats.